Robotic-Assisted Versus Fluoroscopic-Guided Surgery on the Accuracy of Spine Pedicle Screw Placement: A Systematic Review and Meta-Analysis

Spinal fusion is a common method by which surgeons decrease instability and deformity of the spinal segment targeted. Pedicle screws are vital tools in fusion surgeries and advancements in technology have introduced several modalities of screw placement. Our objective was to evaluate the accuracy of pedicle screw placement in robot-assisted (RA) versus fluoroscopic-guided (FG) techniques. The PubMed and Cochrane Library databases were systematically reviewed from January 2007 through to August 8, 2022, to identify relevant studies. The accuracy of pedicle screw placement was determined using the Gertzbein-Robbins (GR) classification system. Facet joint violation (FJV), total case radiation dosage, total case radiation time, total operating room (OR) time, and total case blood loss were collected. Twenty-one articles fulfilled the inclusion criteria. Successful screw accuracy (GR Grade A or B) was found to be 1.02 (95% confidence interval: 1.01 - 1.04) times more likely with the RA technique. In defining accuracy solely based on the GR Grade A criteria, screws placed with RA were 1.10 (95% confidence interval: 1.06 - 1.15) times more likely to be accurate. There was no significant difference between the two techniques with respect to blood loss (Hedges' g: 1.16, 95% confidence interval: -0.75 to 3.06) or case radiation time (Hedges' g: -0.34, 95% CI: -1.22 to 0.53). FG techniques were associated with shorter operating room times (Hedges' g: -1.03, 95% confidence interval: -1.76 to -0.31), and higher case radiation dosage (Hedges' g: 1.61, 95% confidence interval: 1.11 to 2.10). This review suggests that RA may slightly increase pedicle screw accuracy and decrease per-case radiation dosage compared to FG techniques. However, total operating times for RA cases are greater than those for FG cases.

Association between history of lumbar spine surgery and paralumbar muscle health: a propensity score-matched analysis

BACKGROUND CONTEXT

Prior studies have suggested that muscle strength and quality may be associated with low back pain. Recently, a novel magnetic resonance imaging (MRI)-based lumbar muscle health grade was shown to correlate with health-related quality of life scores after spine surgery. However, the potential association between history of lumbar spine surgery and paralumbar muscle health requires further investigation.

PURPOSE

To compare MRI-based paralumbar muscle health parameters between patients with versus without a history of surgery for degenerative lumbar spinal disease.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Consecutive series of patients who presented to the spine surgery clinic of a single surgeon.

OUTCOME MEASURES

MRI-based measurements of paralumbar cross-sectional area (PL-CSA), Goutallier grade, lumbar indentation value (LIV).

METHODS

A retrospective analysis was performed on a consecutive series of patients of a single surgeon, and patients were included based on availability of lumbar MRI. Axial T2-weighted lumbar MRIs were analyzed for PL-CSA, Goutallier classification, and LIV. Measurements were performed at the center of disc spaces from L1 to L5. Patients with and without history of spine surgery were matched based on age, sex, race, ethnicity, and body mass index (BMI) via propensity score matching. Normality of each muscle health variable was assessed using Kolmogorov-Smirnov test. Mann-Whitney U test or independent t-test performed to compare the matched cohorts, as appropriate.

RESULTS

A total of 615 patients were assessed. For final analysis, 89 patients with a history of previous spine surgery were matched with 89 patients without a history of spine surgery. There were no statistically significant differences in age, sex, race, ethnicity, or BMI between the matched cohorts. History of spine surgery was generally associated with worse lumbar muscle health. At all 4 intervertebral levels between L1-L5, PL-CSA was significantly smaller among patients with history of spine surgery. At L4-L5, patients with prior spine surgery had significantly smaller PL-CSA/BMI. Patients with prior spine surgery were found to have greater fatty infiltration of the muscles, with higher average Goutallier grades at levels L1-L2, L2-L3, and L4-L5. In addition, history of spine surgery was associated with smaller LIV at L1-L2, L3-L4, and L4-L5.

CONCLUSIONS

The current study demonstrates that history of lumbar spine surgery is associated with worse paralumbar muscle health based on quantitative and qualitative measurements on MRI. On average, patients with history of spine surgery were found to have smaller cross-sectional areas of the paralumbar muscles, greater amounts of fatty infiltration based on Goutallier classification, and smaller lumbar indentation values.

Predictors of Readmission and Reoperation Following Shoulder Arthroplasty in Patients Under 45 Years of Age

BACKGROUND

The use of shoulder arthroplasty has increased among all age groups, albeit most prominently in older patients. While previous studies have investigated predictors of short-term readmission and reoperation in the general population, there is a paucity of literature available on these in patients under 45 years of age. This study aimed to identify the predictors of 30-day readmission and reoperation following shoulder arthroplasty in patients under 45 years of age.

METHODS

A retrospective query in the American College of Surgeons National Surgical Quality Improvement Program database from 2011 to 2019 was used to identify patients who underwent primary reverse and anatomic total shoulder arthroplasty and hemiarthroplasty. Multivariate logistic regression was used to identify predictors of 30-day readmission and reoperation.

RESULTS

A total of 530 patients were included. Multivariate regression revealed that Black race and Hispanic ethnicity were independent predictors of readmission. Functional dependence, hypertension requiring medication, and prolonged length of stay predicted reoperation. Finally, low hematocrit and prolonged length of stay predicted morbidity.

DISCUSSION

Identifying and accounting for these risk factors for poor outcomes may help improve perioperative risk stratification. As a result, these findings have the potential to reduce healthcare costs associated with readmission and reoperation following shoulder arthroplasty in young patients. Our results also highlight the underlying disparities in healthcare outcomes among racial and ethnic groups that must be considered.

Impact of Navigation on 30-Day Outcomes for Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective database study.

OBJECTIVE

Navigation has been increasingly used to treat degenerative disease, with positive radiographic and clinical outcomes and fewer adverse events and reoperations, despite increased operative time. However, short-term analysis on treating adult spinal deformity (ASD) surgery with navigation is limited, particularly using large nationally represented cohorts. This is the first large-scale database study to compare 30-day readmission, reoperation, morbidity, and value-per-operative time for navigated and conventional ASD surgery.

METHODS

Adults were identified in the National Surgical Quality Improvement Program (NSQIP) database. Multivariate regression was used to compare outcomes between navigated and conventional surgery and to control for predictors and baseline differences.

RESULTS

3190 ASD patients were included. Navigated and conventional patients were similar. Navigated cases had greater operative time (405 vs 320 min) and mean RVUs per case (81.3 vs 69.7), and had more supplementary pelvic fixations (26.1 vs 13.4%) and osteotomies (50.3 vs 27.7%) (P <.001).In univariate analysis, navigation had greater reoperation (9.9 vs 5.2%, P = .011), morbidity (57.8 vs 46.8%, P = .007), and transfusion (52.2 vs 41.8%, P = .010) rates. Readmission was similar (11.9 vs 8.4%). In multivariate analysis, navigation predicted reoperation (OR = 1.792, P = .048), but no longer predicted morbidity or transfusion. Most reoperations were infectious and hardware-related.

CONCLUSIONS

Despite controlling for patient-related and procedural factors, navigation independently predicted a 79% increased odds of reoperation but did not predict morbidity or transfusion. Readmission was similar between groups. This is explained, in part, by greater operative time and transfusion, which are risk factors for infection. Reoperation most frequently occurred for wound- and hardware-related reasons, suggesting navigation carries an increased risk of infectious-related events beyond increased operative time.

Venous Thromboembolism Rates Have Not Decreased in Elective Lumbar Fusion Surgery from 2011 to 2020

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

This study aimed to (1) evaluate for any temporal trends in the rates of VTE, deep venous thrombosis (DVT), pulmonary embolism (PE), and mortality from 2011 to 2020 and (2) identify the predictors of VTE following lumbar fusion surgery.

METHODS

Annual incidences of 30-day VTE, DVT, PE, and mortality were calculated for each of the operation year groups from 2011 to 2020. Multivariable Poisson regression was utilized to test the association between operation year and primary outcomes, as well as to identify significant predictors of VTE.

RESULTS

A total of 121,205 patients were included. There were no statistically significant differences in VTE, DVT, PE, or mortality rates among the operation year groups. Multivariable regression analysis revealed that compared to 2011, operation year 2019 was associated with significantly lower rates of DVT. Age, BMI, prolonged operation time, prolonged length of stay, non-home discharge, anterior fusion, smoking status, functional dependence, and chronic steroid use were identified as independent predictors of VTE following lumbar fusion. Female sex, Hispanic ethnicity, and outpatient surgery setting were identified as protective factors from VTE in this cohort.

CONCLUSIONS

Rates of VTE after lumbar fusion have remained mostly unchanged between 2011 and 2020. Older age, higher BMI, longer operation time, prolonged length of stay, non-home discharge, anterior fusion, smoking, functional dependence, and steroid use were independent predictors of VTE after lumbar fusion, while female sex, Hispanic ethnicity, and outpatient surgery were the protective factors.

Navigated versus conventional pediatric spinal deformity surgery: Navigation independently predicts reoperation and infectious complications

Context

Literature on treating pediatric spinal deformity with navigation is limited, particularly using large nationally represented cohorts. Further, the comparison of single-institution data to national-level database outcomes is also lacking.

Aim

(1) To compare navigated versus conventional posterior pediatric deformity surgery based on 30-day outcomes and perioperative factors using the National Surgical Quality Improvement Program (NSQIP) database and (2) to compare the outcomes of the NSQIP navigated group to those of fluoroscopy-only and navigated cases from a single-institution.

Settings and Design

Retrospective cohort study.

Subjects and Methods

Pediatric patients who underwent posterior deformity surgery with and without navigation were included. Primary outcomes were 30-day readmission, reoperation, morbidity, and complications. The second part of this study included AIS patients < 18 years old at a single institution between 2015 and 2019. Operative time, length of stay, transfusion rate, and complication rate were compared between single-institution and NSQIP groups.

Statistical Analysis Used

Univariate analyses with independent t-test and Chi-square or Fisher's exact test was used. Multivariate analyses through the application of binary logistic regression models.

Results

Part I of the study included 16,950 patients, with navigation utilized in 356 patients (2.1%). In multivariate analysis, navigation predicted reoperation, deep wound infection, and sepsis. After controlling for operative year, navigation no longer predicted reoperation. In Part II of the study, 288 single institution AIS patients were matched to 326 navigation patients from the NSQIP database. Operative time and transfusion rate were significantly higher for the NSQIP group.

Conclusions

On a national scale, navigation predicted increased odds of reoperation and infectious-related events and yielded greater median relative value units (RVUs) per case but had longer operating room (OR) time and fewer RVUs-per-minute. After controlling for operative year, RVUs-per-minute and reoperation rates were similar between groups. The NSQIP navigated surgery group was associated with significantly higher operative time and transfusion rates compared to the single-institution groups.

Comparison of Relative Value Units and 30-Day Outcomes Between Primary and Revision Pediatric Spinal Deformity Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to compare the relative value units (RVUs) and 30-day outcomes between primary and revision pediatric spinal deformity (PSD) surgery.

SUMMARY OF BACKGROUND DATA

PSD surgery is frequently complicated by the need for reoperation. However, there is limited literature on physician reimbursement rates and short-term outcomes following primary versus revision spinal deformity surgery in the pediatric population.

MATERIALS AND METHODS

This study utilizes data obtained from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Pediatric database. Patients between 10 and 18 years of age who underwent posterior spinal deformity surgery between 2012 and 2018 were included. Univariate and multivariate regression were used to assess the independent impact of revision surgery on RVUs and postoperative outcomes, including 30-day readmission, reoperation, morbidity, and complications.

RESULTS

The study cohort included a total of 15,055 patients, with 358 patients who underwent revision surgery. Patients in the revision group were more likely to be younger and male sex. Revision surgery more commonly required osteotomy (13.7% vs. 8.3%, P =0.002).Univariate analysis revealed higher total RVUs (71.09 vs. 60.51, P <0.001), RVUs per minute (0.27 vs. 0.23, P <0.001), readmission rate (6.7% vs. 4.0%, P =0.012), and reoperation rate (7.5% vs. 3.3%, P <0.001) for the revision surgery group. Morbidity rates were found to be statistically similar. In addition, deep surgical site infection, pulmonary embolism, and urinary tract infection were more common in the revision group. After controlling for baseline differences in multivariate regression, the differences in total RVUs, RVUs per minute, reoperation rate, and rate of pulmonary embolism between primary and revision surgery remained statistically significant.

CONCLUSIONS

Revision PSD surgery was found to be assigned appropriately higher mean total RVUs and RVUs per minute corresponding to the higher operative complexity compared with primary surgery. Revision surgery was also associated with poorer 30-day outcomes, including higher frequencies of reoperation and pulmonary embolism.

LEVEL OF EVIDENCE

Level III.

Duration of Back Pain Symptoms and Its Relationship to Paralumbar Muscle Volume

OBJECTIVE

Paralumbar muscle volume has been indicated as an important factor for patients reporting back pain. Our goal was to determine if there is a statistically significant relationship between the duration of patients' back pain symptoms (>12 weeks or ≤12 weeks) and paralumbar muscle volume.

METHODS

In this retrospective cohort study, paralumbar muscles on axial T2-weighted lumbar magnetic resonance images were outlined using ImageJ to determine the paralumbar cross-sectional area (PL-CSA) and lumbar indentation value (LIV) at the center of disc spaces from L1 to L5. The Goutallier classification was determined by the primary author. Quantile regression was performed to compare the PL-CSA, PL-CSA normalized by body mass index, and LIV between the 2 cohorts. Cohort A consisted of patients reporting symptoms ≤12 weeks, and cohort B included patients with symptoms >12 weeks. Negative binomial regression was used to compare Goutallier class.

RESULTS

A total of 551 patients operated on by a single surgeon with lumbar magnetic resonance imaging within the past 12 months and recorded duration of symptoms were included. Cohort A consisted of 229 patients (41.6%), and cohort B included 322 patients (58.4%). Statistical significance was not found at any lumbar level for PL-CSA, PL-CSA normalized by body mass index, Goutallier class, and LIV.

CONCLUSIONS

Our results suggest that duration of symptoms may not be an accurate indicator for lumbar muscle volume. These novel findings are clinically valuable because lumbar muscle volume has been shown to be a marker for recovery. With this information, patients previously believed to be inoperable because of long-standing symptoms can be reevaluated.

Lumbar fusion during the COVID-19 pandemic: greater rates of morbidity and longer procedures

Background

The coronavirus disease 2019 (COVID-19) pandemic has altered the standard of care for spine surgery in many ways. However, there is a lack of literature evaluating the potential changes in surgical outcomes and perioperative factors for spine procedures performed during the pandemic. In particular, no large database study evaluating the impact of the COVID-19 pandemic on spine surgery outcomes has yet been published. Therefore, the aim of this study was to evaluate the impact of the COVID-19 pandemic on perioperative factors and postoperative outcomes of lumbar fusion procedures.

Methods

This retrospective cohort study utilized the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, which was queried for all adult patients who underwent primary lumbar fusion in 2019 and 2020. Patients were grouped into cohorts based on 2019 (pre-pandemic) or 2020 (intra-pandemic) operation year. Differences in 30-day readmission, reoperation, and morbidity rates were evaluated using multivariate logistic regression. Differences in total relative value units (RVUs), RVUs per minute, and total operation time were evaluated using quantile (median) regression. Odds ratios (OR) for length of stay were estimated via negative binomial regression.

Results

A total of 27,446 patients were included in the analysis (12,473 cases in 2020). Unadjusted comparisons of outcomes revealed that lumbar fusions performed in 2020 were associated with higher rates of morbidity, pneumonia, bleeding transfusions, deep venous thrombosis (DVT), and sepsis. 2020 operation year was also associated with longer length of hospital stay, less frequent non-home discharge, higher total RVUs, and higher RVUs per minute. After adjusting for baseline differences in regression analyses, the differences in bleeding transfusions, length of stay, and RVUs per minute were no longer statistically significant. However, operation year 2020 independently predicted morbidity, pneumonia, DVT, and sepsis. In terms of perioperative variables, operation year 2020 predicted greater operative time, non-home discharge, and total RVUs.

Conclusions

Lumbar fusion procedures performed amidst the COVID-19 pandemic were associated with poorer outcomes, including higher rates of morbidity, pneumonia, DVT, and sepsis. In addition, surgeries performed in 2020 were associated with longer operative times and less frequent non-home discharge disposition.

The 5-Item Modified Frailty Index Independently Predicts Morbidity in Patients Undergoing Instrumented Fusion following Extradural Tumor Removal

Introduction

The management of spinal neoplasia consists of surgical, radiation, and systemic options. Little data exist to guide management based on overall health status, which is particularly challenging when patients who could benefit from surgery may be too frail for it. This study's objective was to evaluate the 5-Item Modified Frailty Index (mFI-5) as a predictor of 30-day morbidity in patients undergoing instrumented resection for metastatic extradural spinal tumors.

Methods

Adults undergoing extradural tumor resection from the 2011 to 2019 National Surgical Quality Improvement Program datasets were identified by Current Procedural Terminology codes 63275-63278 with an adjunct instrumentation code (22840-22843). Patients were classified into frailty levels 0, 1, or 2+ based on mFI-5 scores of 0, 1, or 2-5, respectively. The primary outcome was morbidity. Secondary outcomes were readmission and reoperation. Multivariate modeling was utilized to analyze mFI-5 as a predictor of outcomes. The Akaike information criterion (AIC) was used to compare relative-model-fit based on frailty versus individual comorbidity variables to determine the optimal model. Chi-squared and Fisher's exact tests were used to establish significance between individual complications and frailty.

Results

There were 874 patients. Readmission, reoperation, and morbidity rates were 19.5%, 5.0%, 52.3%, respectively. In multivariate analyses, mFI-5=1 (OR: 1.45, SE: 0.31, p=0.036), mFI-5=2+ (OR: 1.41, SE: 0.40, p=0.036), operative time (OR: 1.18, SE: 0.03, p≤0.001), and chronic steroid use (OR: 1.56, SE: 0.42, p=0.037) independently predicted morbidity. Elective surgery (OR: 0.61) was protective. Frailty did not predict readmission or reoperation. Frailty was found to be significantly associated with respiratory complications, urinary tract infections, cardiac events, and sepsis/septic shock specifically.

Conclusions

mFI-5=1 independently predicted 45% increased odds of morbidity. mFI-5=2+ independently predicted 41% increased odds of morbidity. Further, every 30 additional minutes of operative time predicted 18% increased odds of morbidity, suggesting an increased risk of site-related complication events. Taken together, the mFI-5 serves as a valid predictor of morbidity in patients with extradural tumor undergoing instrumented excision.

Discharge to Rehabilitation Predicts Increased Morbidity in Patients Undergoing Posterior Cervical Decompression and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim was to compare 30-day readmission and postdischarge morbidity for posterior cervical decompression and fusion (PCDF) in patients who were discharged to home versus rehabilitation.

SUMMARY OF BACKGROUND DATA

An increasing number of patients are being discharged to postacute inpatient care facilities following spine surgery. However, little research has been performed to evaluate the effect of this trend on short-term outcomes.

MATERIALS AND METHODS

Patients who underwent PCDF from 2011 to 2018 were identified using the National Surgical Quality Improvements Program (NSQIP)-database. Regression was utilized to compare primary outcomes between home and rehabilitation groups and to control for predictors of outcomes.

RESULTS

We identified 8912 patients. Unadjusted analysis revealed that rehabilitation-discharge patients had greater readmission (10.4% vs. 8.0%, P=0.002) and postdischarge morbidity (7.1% vs. 4.0%, P<0.001) rates. After controlling for patient-related factors, rehabilitation-discharge independently predicted postdischarge morbidity (P<0.001, odds ratio=2.232). Readmission no longer differed between groups (P=0.071, odds ratio=1.311). Rates of discharge to rehabilitation increased from 23.5% in 2011 to 25.3% in 2018, while postdischarge morbidity rates remained stagnant.Patients discharged to rehabilitation were older (66.9 vs. 59.4 y); more likely to be African American (21.4% vs. 13.8%) and have diabetes (27.1% vs. 17.5%), steroid use (6.4% vs. 4.7%, P=0.002), and American Society of Anaesthesiologists (ASA)-class ≥3 (80.2% vs. 57.7%); less likely to be male (53.9% vs. 57.4%, P=0.004) and smokers (20.3% vs. 26.6%); and had greater operative time (198 vs. 170 min) and length of hospital stay (5.9 vs. 3.3 d) (P<0.001).

CONCLUSIONS

Despite controlling for significant factors, discharge to rehabilitation independently predicted a 2.2 times increased odds of postdischarge morbidity. Rates of discharge to rehabilitation increased overtime without an appreciable decrease in postdischarge morbidity, suggesting that greater resources are being utilized in the postacute care period without an obvious justification. Therefore, home-discharge should be prioritized after hospitalization for PCDF when feasible. These findings are notable in light of reform efforts aimed at reducing costs while improving quality of care.

Impact of Discharge to Rehabilitation on Postdischarge Morbidity Following Multilevel Posterior Lumbar Fusion

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

The objective of this study was to compare 30-day postdischarge morbidity for 3-or-more level (multilevel) posterior lumbar fusion in patients who were discharged to home versus rehabilitation.

SUMMARY OF BACKGROUND DATA

Spine surgery has been increasingly performed in the elderly population, with many of these patients being discharged to rehabilitation and skilled nursing facilities. However, research evaluating the safety of nonhome discharge following spine surgery is limited.

MATERIALS AND METHODS

Patients who underwent multilevel posterior lumbar fusion from 2005 to 2018 were identified using the National Surgical Quality Improvement Program (NSQIP) database. Regression was utilized to compare primary outcomes between discharge disposition and to evaluate for predictors thereof.

RESULTS

We identified 5276 patients. Unadjusted analysis revealed that patients who were discharged to rehabilitation had greater postdischarge morbidity (5.6% vs. 2.6%). After adjusting for baseline differences, discharge to rehabilitation no longer predicted postdischarge morbidity [odds ratio (OR)=1.409, confidence interval: 0.918-2.161, P=0.117]. Multivariate analysis also revealed that age (P=0.026, OR=1.023), disseminated cancer (P=0.037, OR=6.699), and readmission (P<0.001, OR=28.889) independently predicted postdischarge morbidity.

CONCLUSIONS

Thirty days morbidity was statistically similar between patients who were discharged to home and rehabilitation. With appropriate patient selection, discharge to rehabilitation can potentially minimize 30-day postdischarge morbidity for more medically frail patients undergoing multilevel posterior lumbar fusion. These results are particularly important given an aging population, with a great portion of elderly patients who may benefit from postacute care facility discharge following spine surgery.

Is academic department teaching status associated with adverse outcomes after lumbar laminectomy and discectomy for degenerative spine diseases?

BACKGROUND CONTEXT

Lumbar laminectomy and discectomy surgeries are among the most common procedures performed in the United States, and often take place at academic teaching hospitals, involving the care of resident physicians. While academic institutions are critical for the maturation of the next generation of attending surgeons, concerns have been raised regarding the quality of resident-involved care. There is conflicting evidence regarding the effects of resident participation in teaching hospitals on spine surgery patient outcomes. As the volume of lumbar laminectomy and discectomy increases, it is imperative to determine how academic status impacts clinical and economic outcomes.

PURPOSE

The purpose of this study is to determine if lumbar laminectomy and discectomy surgeries for degenerative spine diseases performed at academic teaching centers is associated with more adverse clinical outcomes and increased cost compared to those performed at nonacademic centers.

STUDY DESIGN/SETTING

This study is a multi-center retrospective cohort study using a New York Statewide database.

PATIENT SAMPLE

We identified 36,866 patients who met the criteria through the New York Statewide Planning and Research Cooperative System who underwent an elective lumbar laminectomy and/or discectomy in New York State between January 1, 2009 and September 30, 2014.

OUTCOME MEASURES

The primary functional outcomes of interest included: length of stay, cost of the index admission; 30-day and 90-day readmission; 30-day, 90-day, and 1-year return to the operating room.

METHODS

International Classification of Diseases, Ninth revision codes were utilized to define patients undergoing a laminectomy and/or discectomy who also had a diagnosis code for a lumbar spine degenerative condition. We excluded patients with a procedural code for lumbar fusion, as well as those with a diagnosis of scoliosis, neoplasm, inflammatory disorder, infection or trauma. Hospital academic status was determined by the Accreditation Council for Graduate Medical Education. Unique encrypted patient identifiers allowed for longitudinal follow-up for readmission and re-operation analyses. We extracted charges billed for each admission and calculated costs through cost-to-charge ratios. Logistic regression models compared teaching and nonteaching hospitals after adjusting for patient demographics and comorbidities.

RESULTS

Compared to patients at nonteaching hospitals, patients at teaching hospitals were more likely to be younger, male, non-Caucasian, be privately insured and have fewer comorbidities (p<.001). Patients undergoing surgery at teaching hospitals had 10% shorter lengths of stay (2.7 vs. 3.0 days, p<.001), but 21.5% higher costs of admission ($13,693 vs. $11,601 p<.001). Academic institutions had a decreased risk of return to the operating room for revision procedures or irrigation and debridement at 30 days (OR:0.70, 95% confidence interval [CI]: 0.60-0.82, p<.001), 90 days (OR:0.75, 95%CI: 0.66-0.86, p<.001), and 1 year (OR:0.84, 95%CI: 0.77-0.91, p<.001) post index procedure. There was no difference in 30- and 90-day all-cause readmission, or discharge disposition between the two groups.

CONCLUSIONS

Elective lumbar laminectomy and discectomy for degenerative lumbar conditions at teaching hospitals is associated with higher costs, but decreased length of stay and no difference in readmission rates at 30- and 90-days postoperatively compared to nonteaching hospitals. Teaching hospitals had a decreased risk of return to the operating room at 30 days, 90 days and 1 year postoperatively. Our findings might serve as an impetus for other states or regions to compare outcomes at teaching and nonteaching sites.

Parathyroidectomy via bilateral cervical exploration: a retrospective review of 866 cases

INTRODUCTION

Parathyroidectomy via cervical exploration is an effective primary-modality treatment for hyperparathyroidism, with cure rates of greater than 95%. We retrospectively reviewed 866 consecutive parathyroidectomies performed by a single surgeon between 1960 and 1997. We attempted to describe the polymorphic variation in multiglandular disease, the anatomic locations of pathologic glands, and the operative strategy and techniques which we believed were important to minimizing morbidity and maximizing curative success.

METHODS

The cases of 329 males and 537 females (age, 1-88 years) were reviewed. There were 766 operations performed: primary hyperparathyroidism (713), tertiary hyperparathyroidism (100), reoperations (53). The strategy for primary exploration includes a bilateral neck exploration, early recurrent laryngeal nerve skeletonization, and identification of at least four glands.

RESULTS

Normocalcemia was achieved in 98.2% of cases after initial cervical exploration. Persistent hypercalcemia occurred in 7 patients (<1%). Nine patients (1%) suffered persistent postoperative hypocalcemia. Unilateral recurrent laryngeal nerve injury occurred in two patients (<1%). Other perioperative complications included: reoperation for hematoma, repaired carotid artery injury, unexplained dysphagia, pneumothorax, deep venous thrombosis, and aspiration pneumonia. There were two mortalities (<1%) attributable to severe, comorbid disease. Ectopic glands were found in 120 cases. The frequency of glands at these sites were as follows: mediastinal (4.9%), intrathymic (8.4%), intrathyroid (6.7%), and retroesophageal/retrotracheal (3.5%). Thyroid resections provided diagnosis of concomitant thyroid carcinoma in 8.0% of resected patients. The pathology of patients with primary hyperparathyroidism (PHPT) consisted of single adenomas (77.2%), hyperplasia (21.0%), normal glands (1%), double adenomas (<1%), and parathyroid carcinoma (<1%). The distribution of adenomas was as follows: left upper, 25.3%; left lower, 27.3%; right upper, 26.8%; right lower, 20.6%. Hyperplastic glands were found in ectopic positions as follows: intrathymic (7.5%), intrathyroid (11.3%), mediastinal (2.5%), and retroesophageal/retrotracheal (0%). The average volume difference between the largest and smallest hyperplastic gland of each case was 1.80 + 4.40 cm3. Reoperations were performed upon 53 referred patients and 7 patients after failed exploration. Normocalcemia was attained in 98.3% of cases. Glandular pathology was identified in the previous operative field in 52 patients (86.7%). Adenomas were identified in 56.0% (n = 23) and hyperplasia in 39.0% (n = 16).

CONCLUSIONS

In our series, we were able to attain normocalcemia in 98.2% of cases after initial cervical exploration. We believe that identification of four glands, an exhaustive search of ectopic sites, bilateral exploration, and liberal use of biopsy and intraoperative frozen section were essential to curative success. The pathologist should identify parathyroid tissue in the specimen and differentiate the "abnormal" from "normal" gland. Morphologic criteria alone cannot be used because of polymorphic variation in hyperplasia in which pathologic glands may appear normal. Early identification of the recurrent laryngeal nerve allows for a safer neck exploration by alerting the surgeon to the location and course of the nerve. A bilateral approach does not contribute increased morbidity from recurrent laryngeal nerve injury.

Face and neck neurogenic neoplasms

Surgeons should be aware that any mass in the region of the cranial nerves, brachial plexus, cervical sympathetic plexus, or a major peripheral nerve can be of neurogenic origin. Solitary neurogenic tumors of the head and neck can simulate metastatic masses or congenital lesions. If they are resected unrecognized and/or without regard to their nerve origin, major and permanent nerve defects can unnecessarily occur. Thirty-two patients, 16 males and 16 females, ranging in age from 5 to 69 years, had 33 extracranial solitary neurogenic neoplasms resected. The nerves involved were the cervical sympathetic plexus in 7 patients, branchial plexus in 6, spinal accessory nerve in 5, vagus nerve in 4, hypoglossal nerve in 3, facial nerve in 2, and 6 other nerves in 1 patient each. The technique is to dissect out the neurilemoma without destroying the nerve sheath or nerve trunk. Despite careful dissection, the four patients with masses of the vagus nerve had permanent ipsilateral cord paralysis.

Anastamoses and bifurcations of the recurrent laryngeal nerve--report of 1177 nerves visualized

One thousand seventy-seven recurrent laryngeal nerves were observed in 719 patients. Seven hundred forty-seven nerves bifurcated or trifurcated over 0.5 cm inferior to the cricoid cartilage (63%). Of these, 170 patients had bilateral nerve bifurcations. Thirty-nine per cent of the patients had bilateral bifurcations when one side bifurcated. Eleven patients had direct laryngeal nerves, two of which bifurcated. Five of these 11 patients also had a recurrent and direct laryngeal nerve. Seven patients had recurrent laryngeal nerves, all on the right side, receiving branches directly from the vagus nerve 6-14 cm from the cricoid. Damage to any filaments to or from the recurrent laryngeal nerve can cause vocal cord paralysis. Damage to branches to the esophagus from the recurrent laryngeal nerve can cause dysphagia.

Incidental preclinical hyperparathyroidism identified during thyroid operations

The entity of preclinical hyperparathyroidism has never been clearly investigated. The authors believe that the incidence of pathologic abnormalities of the parathyroid glands before the development of any symptoms or hypercalcemia (serum calcium > 12.0 mg/dl) is more frequent than has been reported. Over a 14-year period, parathyroid glands were examined during thyroid operations in over 800 patients. Serum calcium and phosphorous levels were measured in all patients preoperatively. Thirty-six patients had additional parathyroid operations for a preclinical form of hyperparathyroidism, defined by abnormal appearing parathyroid glands at the time of thyroid surgery. None of the 36 patients had symptoms of hyperparathyroidism preoperatively. Nine patients had borderline hypercalcemia (serum calcium 10.6 to 12.0 mg/dl), and the remainder were considered normocalcemic. The average age was 53 (range 21 to 75) with a male to female ratio of 1:3. Nine of the 36 patients had thyroid cancer. There were eight patients with parathyroid adenoma and 28 patients with parathyroid hyperplasia. Of 13 patients who had a history of neck irradiation, five had parathyroid adenoma and eight had parathyroid hyperplasia. Only two patients with parathyroid hyperplasia remain on calcium medication. Since preoperative normocalcemia does not preclude the presence of parathyroid pathology, the authors urge careful identification and examination of the parathyroid glands during thyroid operations. It adds little time to the procedure. Excision of parathyroid disease along with the thyroid gland can be performed safely and prevents the need for further operation with its associated morbidity.

Fifty-three reoperations for hyperparathyroidism

Fifty-three patients, 35 with persistent and 7 with recurrent hyperparathyroidism, had parathyroid surgery. There were 11 patients who had prior thyroid surgery before being identified as having hyperparathyroidism. Forty patients had parathyroid adenomas and 13 (8 dialysis patients) had parathyroid hyperplasia. Thallium-210-iodine 123 subtraction scanning proved to be the most accurate in localizing parathyroid adenomas (60 percent) but not parathyroid hyperplasia. Resection of 3 3/4 parathyroid glands in primary parathyroid hyperplasia and total parathyroidectomy with parathyroid autotransplantation in tertiary parathyroid hyperplasia are the treatments of choice and would have prevented reoperation in this group. Careful neck exploration, resection of the thymus, and even thyroidectomy would probably have led to the correct location of the missed parathyroid adenomas. Mediastinotomy should not be performed at initial surgery. A careful history and preoperative calcium and phosphorus determinations in all thyroid surgery patients will reveal occult hyperparathyroidism. Twenty-one such patients were identified in our overall parathyroid series.

Thyroglossal duct cysts. A thirty year experience with emphasis on occurrence in older patients

A total of 79 patients (39 female and 40 male) underwent the Sistruck procedure for thyroglossal duct cysts. Twenty-eight percent of the patients were over 50 years of age and 10 percent were over 60. The age range was 16 months to 82 years. Three patients had thyroidectomies, two of which were for carcinoma, along with resection of a thyroglossal duct cyst. Two patients, one diagnosed preoperatively by needle biopsy, had papillary carcinoma in thyroid tissue of the cyst wall. The length of time from cyst discovery to surgery was the same for patients over 10 years of age. We suggest needle biopsy of all neck masses and also elective operation in a patient of any age, once a diagnosis of thyroglossal duct cysts is made. The Sistrunk procedure is the operation of choice.

The clinical significance of the various anastomotic branches of the facial nerve. Report of 100 patients

During parotid dissection, we have found significant variations in the facial nerve branchings that have not been previously reported. One hundred patients, 48 males and 52 females, had their facial nerve photographed and/or diagrammed during parotid surgery. Ninety-nine patients had facial nerve configurations that could be divided into five main types. One nerve could not be classified into any of these types because of a bizarre configuration. Twenty-four percent of patients had a straight branching pattern (type I); 14% of patients had a loop involving the zygomatic division (type II); 44% of patients had a loop involving the buccal division (type III); 14% of patients had a complex pattern with multiple interconnections (type IV); and 3% of patients had two main trunks, one major and one minor (type V). Familiarity with these common variations in facial nerve anatomy is an absolute necessity for the operating surgeon.

Extralaryngeal division of the recurrent laryngeal nerve. Report on 400 patients and the 721 nerves measured

Seven hundred twenty-one recurrent laryngeal nerves were visualized in 400 patients having thyroid or parathyroid surgery. Four hundred twenty-one nerves (58 percent) bifurcated or trifurcated more than 0.5 cm from the cricoid cartilage. Ninety-seven patients had bilateral bifurcations, and 10 patients had trifurcations. Six patients had direct laryngeal nerves, all on the right side. One patient had a direct laryngeal and a recurrent laryngeal nerve simultaneously, and one patient had a bifurcated recurrent laryngeal nerve with an accessory vagus nerve joining it 13.5 cm from the cricoid cartilage. Damage to any of the filaments of the recurrent laryngeal nerve to the cricothyroid musculature or to or from a variant direct laryngeal nerve or variant vagus nerve connection can cause vocal cord paralysis. Damage to any branches of the recurrent laryngeal nerve to the esophagus can cause dysphagia. Therefore, if possible, all branches of the recurrent laryngeal nerve, no matter how small, should be preserved.

Needle aspiration of nonfunctioning parathyroid cysts

Parathyroid cysts, appearing as thyroid masses, have been previously diagnosed at operation or by permanent histologic specimens. With the advent of ultrasound and fine-needle biopsies, these very rare cysts can now be diagnosed by needle aspiration. The pearly clear fluid of a parathyroid cyst contrasts with the sanguineous or even chocolate-brown fluid of a thyroid cyst. The high parathyroid hormone (PTH) level of the fluid confirms the diagnosis, and a blood calcium level determines its function or nonfunction in the patients. Of our seven nonfunctioning parathyroid cysts, the first three were diagnosed by operation and the other four by needle aspirations. The PTH determination ranged from 20,000 to 42,000 pg/mL. We suggest that needle aspiration, rather than operation, be the treatment of choice.

Salivary gland tumors and previous radiotherapy to the head or neck. Report of a clinical series

To estimate what proportion of patients with newly diagnosed salivary gland tumors may have radiation-related disease, we interviewed all 275 patients in a surgical practice who had salivary gland resections during an 8 year period. Patients were asked about previous radiation treatment to the head and neck. Thirty-one patients (11 percent) had both an incident salivary gland tumor and a history of significant exposure. Four of these patients (13 percent) had multiple primary tumors of the salivary glands. The implications and generalizability of these findings have been discussed herein.

Parathyroidectomy. Review of 338 consecutive cases for histology, location, and reoperation

Three hundred thirty-eight consecutive parathyroidectomies for hyperparathyroidism were performed over a 22 year period. There were 53 dialysis patients (31 male and 22 female), 285 patients (165 female and 120 male) with primary hyperparathyroidism, 55 patients (19 percent) with parathyroid hyperplasia, and 230 patients with 236 parathyroid adenomas. The location of the adenomas were right upper in 57, right lower in 59, left upper in 60, and left lower in 60. Forty-three patients of the last 194 operated on had histories of childhood head and neck irradiation (21.6 percent), 34 patients (79.6 percent) had associated thyroid disease, and there were 10 with thyroid carcinomas. In the 285 patients, 54 percent had thyroid disease, and 18 had thyroid carcinomas. Twenty-three patients required reoperation for persistent or recurrent hypercalcemia, and 19 neck reexplorations and 6 mediastinotomies were performed. The identification and biopsy as indicated of all four parathyroid glands at initial neck exploration would have prevented over 70 percent of reoperations.

Extralaryngeal divisions of the recurrent laryngeal nerve. Surgical and clinical significance

Extralaryngeal branches of the recurrent laryngeal nerve have been noted in the literature, but frequently the researchers fail to indicate with accuracy the site of bifurcation. The current study was undertaken to designate the exact level of bifurcation of the recurrent laryngeal nerve, with more precise localization using a standard anatomic landmark. A prospective study based on 83 surgical patients was performed. The location of all nerves was measured using the inferior border of the cricoid cartilage as the anatomic landmark. A total of 153 recurrent laryngeal nerves were observed. Sixty-three (41.2 percent) bifurcated or trifurcated into extralaryngeal branches. Of these, there were four instances of trifurcations. The remaining 59 nerves bifurcated. Of these, 14 nerves bifurcated into equal-sized branches which went in an anterior or posterior direction. The remaining 45 nerve bifurcations indicated that 39 (86.7 percent) of the small branches went in a posterior direction, whereas only 6 (13.3 percent) of the large branches went in that direction. Surgical and clinical implications of this finding were discussed. Two instances of a "nonrecurrent" laryngeal nerve (that occurred on the right side) were also noted. The results of this study demonstrate conclusively that extralaryngeal branches of the recurrent laryngeal nerve are not an anatomic rarity. Therefore, thyroid surgery must include identification and preservation of the recurrent laryngeal nerve and all of its divisions.

Parathyroid autotransplantation in patients with parathyroid disease and total thyroidectomy. Indications in 117 cases

Parathyroid autotransplantation is a known and increasingly utilized procedure. It is indicated in patients with primary parathyroid hyperplasia, in patients with primary hypercalcemia who have normal parathyroid tissue devascularized during surgery, in patients with secondary and tertiary parathyroid hyperplasia, and in patients with total thyroidectomy when normal parathyroid tissue is accidentally or unavoidably removed or completely devascularized. No normal viable parathyroid tissue should be autotransplanted. This procedure was performed in 13 dialysis patients, 27 primary hypercalcemic patients and 77 patients with thyroidectomy. The hypercalcemic patients had autotransplantations into muscle pockets in the volar surface of the forearm, while the thyroidectomy patients had autotransplantation into the sternocleidomastoid muscles. The application of parathyroid autotransplantation is a major technical and physiologic breakthrough in the field of thyroid and parathyroid surgery. It should greatly reduce the morbidity associated with permanent hypocalcemia in this type of extensive surgery.

Thyroid and associated polyglandular neoplasms in patients who received head and neck irradiation during childhood

One hundred fifty-one patients with a history of childhood irradiation to the head, neck, and thorax had neck explorations (142 for "cold" thyroid nodules and 9 for hypercalcemia). Fifty-nine of the patients had thyroid carcinoma, and associated glandular tumors were found in 20 others. In addition, 6 female patients developed breast carcinoma; 4 of these women also had thyroid carcinoma. In this series, 48.6% of the patients irradiated for acne and 36.4% with tonsil and adenoid irradiation developed thyroid carcinoma, but only 10.5% with thymic irradiation did so. It is suggested that the workup on these patients include not only complete thyroid and parathyroid testing, but also a careful examination of all salivary glands, both major and minor. Women should have thorough breast examinations and should perhaps be followed as if they were in the potentially high-risk breast group. When thyroid surgery is performed, a total thyroidectomy is recommended.

The malignant "cold" nodule of the thyroid

From 1958 to 1976, 910 patients with cold nodules of the thyroid underwent thyroid surgery (714 females, 196 males). Thyroid carcinoma was present in 202 patients (22.2 per cent) (149 females, 20.9 per cent; 53 males, 27 per cent). Rate of malignancy in an age group was greatest in patients older than seventy years (19 of 47 patients, 40.4 per cent) followed by patients twenty-one to thirty years of age (37 of 125 patients, 29.6 per cent); 90 per cent of all patients were from twenty-one to seventy years of age. Blacks had a lower rate of thyroid carcinoma than Caucasians. Data from the Cancer Surveillance Group also showed age-adjusted incidence rates in blacks in Los Angeles County to be lower than that of Caucasians.

Parotid area swelling caused by a prominent transverse process of atlas

Among 1,500 parotid sialography examinations, the diagnosis of a parotid mass caused by a prominent transverse process of the atlas was made in 18 patients. The diagnosis was confirmed in one patient who insisted on surgical exploration. The remaining 17 patients required no surgical procedure. Many head and neck surgeons have unwittingly operated on such cases with frustrating results. Hopefully, roentgenographic findings will assist in the confirmation of the diagnosis and eliminate the need for such operations.

Unusual lesions of the parotid gland

Ten unusual cases of parotid tumors are added to the literature from a series of 318 consecutive parotidectomies. These 10 cases are: 3 branchial cleft cysts; a lipoma; a lymphangioma; a hemangiopericytoma; a Boeck sarcoid; a metastasizing basal cell carcinoma; a lymphoma of the parotid; and a metastatic adenocarcinoma from the left breast to the right parotid. The lymphoma, Case 1, is also an example of some other cranial nerve taking over the function of the facial nerve when it is destroyed in early childhood. Though most tumors of the parotid gland are of the mixed type, many suprising findings are possible. The pathology report may be the first clue to a hidden systemic disease.